This invention relates generally to refrigeration devices, and more particularly, to control systems for refrigerators.
Current appliance revitalization efforts require electronic subsystems to operate different appliance platforms. For example, known household refrigerators include side-by-side single and double fresh food and freezer compartments, top mount, and bottom mount type refrigerators. A different control system is used in each refrigerator type. For example, a control system for a side-by-side refrigerator controls the freezer temperature by controlling operation of a mullion damper. Such refrigerators may also include a fresh food fan and a variable or multi-speed fan evaporator fan. Top mount refrigerators and bottom mount refrigerators are available with and without a mullion damper, the absence or presence of which affects the refrigerator controls. Therefore, control of the freezer temperature in top and bottom mount type refrigerators is not via control of a mullion damper.
In addition, each type of refrigerator, i.e., side-by-side, top mount, and bottom mount, have different optimal control algorithms for most efficiently controlling refrigerator operation. Conventionally, different control systems have been employed to control different refrigerator platforms, which is undesirable from a manufacturing and service perspective.
In an exemplary embodiment, an adaptive control system is provided for a refrigeration system including a fresh food compartment and a freezer compartment with a damper establishing flow communication therebetween, a sealed system for forcing cold air through the refrigerator compartments and having an evaporator fan and a fresh food compartment fan. The controller is operatively coupled to the damper, the evaporator fan and the fresh food fan, and the controller is configured to accept a plurality of control inputs, determine a state of the refrigeration system in a two-dimensional logic control grid based upon the control parameter inputs, and execute an optimal control algorithm for the determined state of the refrigeration system.
More specifically, the controller includes a processor and a memory, and is configured to read data corresponding to a fresh food compartment condition and data corresponding to a freezer compartment condition. The memory is loaded with a two-dimensional logic control grid including a first axis and a second axis corresponding to fresh food compartment temperature and freezer compartment temperature, respectively. The axes of the grid are partitioned into a plurality of temperature ranges for the respective refrigerator compartments, and the partitions of the first and second axes define a plurality of states in the control grid. Each state contains control parameter settings to maintain that state in the control grid, or to drive the refrigerator into another state in the control grid, and ultimately to drive the refrigerator to a steady state wherein target temperatures are maintained in each of the fresh food compartment and the freezer compartment.
The controller is configured to periodically determine actual fresh food compartment and freezer compartment temperatures, input the temperatures to the control grid, and locate an applicable state in the control grid based upon the determined temperatures. The controller also reads current control parameter setting from system memory, and compares the current control parameters to desired control parameter values determined by the located control grid state. The control parameters are then adjusted to the desired values if the current values are different than the desired values.
The grid may be dynamically reconfigured to form a desired number of states in the control grid by setting partition points of the first and second axes equal to one another or to values that effectively eliminate certain grid states in operation. The controller is also configured to automatically configure itself to a refrigerator platform in which it is installed. A single adaptive control system is therefore provided that is applicable to a variety of refrigerator platforms.